This post on Linkedin got me wondering what the time savings would have been if Hassan Adinan Sharif (41, Tanzania) and Victor Akpabli (30, Ghana) had similar time trial equipment as the top riders.
Not knowing how to model the CdA of each of these scenarios in Rwanda, I asked ChatGPT and Claude (for comparison) what time they would have saved if they had TT bikes, helmet, skinsuit, etc. I also uploaded the course profile to give it some context.
Both models gave a similar outcome:
- On flat/fast sections, they’d save ~2–2.5 minutes per 10 km.
- On climbs, savings are marginal (seconds, not minutes).
- Over the 40.6 km course, realistic gain = 6–8 minutes compared to riding a normal road bike setup.
5. Adjusted times
- Victor Akpabli (Ghana): 1:10:11 – ~7 min = ~1:03:00
- Hassan Sharif (Tanzania): 1:09:15 – ~7 min = ~1:02:15
That would put them in mid-30th positions (instead of 43rd for Sharif, and 46th for Victor (Cudjoe on the results sheet, Akpabli on the Velon photo)
If this is accurate (which sounds plausable), that still leaves them about 12–13 minutes behind Remco.
@Robert_Chung - they even referenced your model (without your permission I assume)
" Published research and field data (Chung method, track testing, pro vs amateur TT studies) suggest:
- Full TT setup (frame, wheels, helmet, skinsuit, shoe covers, aero extensions) vs road bike with standard kit = ~15–20% faster in flat/rolling TTs.
- The gain is reduced on climbs, since aerodynamics matter less at lower speeds. On a hilly course like this, expect ~10–12% net time savings over 40 km."
I’m curious if you think this is accurate @Robert_Chung. It’s an interesting thought experiment and puts things into perspective.
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It’s hard to know exactly but we can probably put broad bands on the estimate. The ChatGPT/Claude estimates are equivalent to around 12 to 15 seconds per km on flat/downhill, but this course wasn’t flat (at all). But let’s ignore the climbing parts, and just look at the flat parts. If you were an “average-sized” rider (not tiny, not huge), and you just slapped clip-ons (or mini-clipons, as Sharif appeared to be using) on your road bike without any other optimization, you might be able to get a CdA of maybe 0.3 to 0.33 or so, and you’d be uncomfortable so you might (probably will) take a power hit. With a little bit of practice and acclimation to the position you might be able to get to highish 0.2x, like maybe 0.28, and less of a power hit. On a standard TT bike without much optimization but some acclimation and minimal cockpit adjustments, maybe 0.25 and possibly even less of a power hit. On a highly optimized TT setup with excellent tires and skinsuit and drivetrain and helmet etc., maybe 0.20 and Crr ~ 0.003. Remco is pretty small and highly optimized so his CdA on a UCI-legal TT bike and all other accoutrements is probably < 0.20.
So, kinda surprisingly, the ChatGPT/Claude estimates for flat ground calm air improvement of 12-15 sec/km is probably in the right ballpark.
Kigali isn’t at sea level (that’s an understatement – it’s at ~1600m ASL) but this chart gives you an idea of the improvment possible.
Remco’s winning time on the Kigali TT course was just a bit under an hour, so his overall average speed was about 80% of what it would have been on the flat, i.e., he took around 120% longer than he would have done had the course been flat.
Of course, you can’t just put a rider on a TT bike even with the right skinsuit and shoe covers and helmet and expect that they will have the right position, nor that they will be able to produce close to their road bike power. The bottom line is that there is definitely a technology advantage in racing TT s, but the the technology advantage may not be definitive, nor the duration you can hold that position indefinite.
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Thanks for the response Robert. Very interesting.
The original LinkedIn post had me wondering how much of a disadvantage these two riders had, and while it was quite a bit, it wouldn’t have put them close to a top 10 or 20 position. They still needed Remco’s legs, support and genetics.
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My brother once said that a TT bike wouldn’t turn a donkey into a race horse but it did turn me from a donkey into a horse’s ass.
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